Improvement in bit-stocks



UNITED STATES PATENT 'CFFIGE HUBERT C. HART, OF UNIONVILLE, CONNECTICUT.

IMPROVEMENT IN BIT-STOCKS.

Specification forming part of Letters Patent No. 149,306, dated April '7, 1874; application filed Feburary 27, 1874.

To all whom it may concern:

Be it known that I, HUBERT C. HART, of Unionville, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Bit-Stocks, of which the followingis a specification, reference being had to the accompanying drawings, where Figure 1 is a view of the whole bit-stock. Fig. 2 is a .view of the clamp or chuck in central vertical section. Fig. 3 is a view of the mouth of the chuck.

The invention consists in a combination of parts whereby the bit is securely clamped in the stock and readily detached therefrom.

The letter (0 indicates the main part or body of the bit-stock; a, the button on the upper end of the same. To the lower end of the part a is attached the chuck-shell b, into the upper end of which runs the thumb-screw c, the screw-thread on its lower end taking into the nut d, to which are pivoted the jaws e e, which are fitted on their opposing faces to grasp and hold the shank of an auger-bit. The spring f serves to press the nut and the jaws constantly downward and outward. The jaws are held from turning in the shell Z) by the pin 0 projecting from one of the jaws into the mortise b in the shell. The mouth of the shell at g is made with a flare, and the jaws have a corresponding swell, so that as the jaws are moved inward by means of the thumbscrew they will be pressed together, and when moved outward, the jaws are permitted to open, being pressed apart by the spring It. The shank of the bit is introduced between the jaws while they are opened, and then, by

means of the thumb-screw, the hold of thec. HART.

\Vitnesses:

WM. E. SIMoNDs, I S. J. SIMoNDs. 

